Process of preserving wood.



snares a'rnn'r FFIGE.

PROCESS OF PRESE BVING WOOD.

{Specification of Letters Patent.

Patented Aug. 6, 1907.

Application filed April 1.1907. Serial No. 365.797.

To all whom it may concern:

Be it known that I, SYLVESTER W. humor, 9. citizen of the United States, residing at New Orleans, in the parish of Orleans and State of Louisiana, have invented certain new and useful improvements in Processes of Preserving Wood; and do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to snake and use the same, reference being had to the accompanying drawings, and to the letters and figures gif reference marked thereon, which form a part of this specification.

My invention relates to the preservation ofwood.

Its object is to render the wood uniformly absorbant, and to secure aunifo'rm distribution or" th' total allotted quantity of preservative so as to obtain an equal quantity of preservative per unit of measure of the wood tot 5c preserved. v To the accomplishment of the foregoing and such other objects as may hereinafter appear the invention consists in the features hereinafter described."

- and then the charge at the top of the cylinder becomes submerged. The porosity and absorbent ability of wood varies greatly. Qlose grain, non-absorbent and comparatively green wood will take up a smaller amount of the preserving'tluid than will be taken up by comparatively dry, open grain and absorbent timber. Owing to the natural conditions of the timber, and the practical conditions of operation, it is impracticable to assort the timber according to its degree of porosity or ability to absorb the preserving fluid, so as to obtain a charge of wood in the cylinder v for all of which the conditions and requirements will be the same. Consequently there is a material variation in the amount of preserving fluid that each of the varieties of wood in the cylinder will absorb or take up from the total allotment of the fluid for the cylinder charge under treatment. Hence the conditions mentioned render it practically impossible under the usual method to obtain a uniform distribution of a small quantity of the preserving fluid throughout any given cylinder charge. To make it possible to fill the cylindcr with the preserving fluid and obtain a uniform distribution of the fluid th roughontall the wood constituting the charge and having different degrees of porosity or power of absorption is thepurpose of the-present invention.

In carrying out the present process, the wood is subjected in a closed vessel or cylinder to an air presof the wood, and with the amount of preservative it is proposed to force into each cubic foot of the wood under treatment. Without lowering materially this air pressure which fills the cells of the wood with air, the preserving fluid, for instance creosote, is next introduced into the cylinderand caused to fill the cyl with the fluid without the wood in the bottom of the cylinder, or the more porous woods, absorbing undue quantities of the preserving fluid, or more of the fluid than other portions of the wood or charge, the cylinder being provided with suitable pressure gages to indicate the pressure within the cylinder. This is due the wood in the cylinder is practically uniform and consequently the conditions substantially the same for allportions of the wood constituting the el arge.

. The cells of the Wood having been filledifwlth compressed air sufficient to prevent the wood absorbing the preservative fluid, the next step is to fill the chamber with the preservative. To this end, the cylinder being provided with a relief or pop-off valve set to release at a predetermined pressure, the preservative is forced by a suitable pump, into the cylinder from a tank of given dimensions, the dimensions of the tank enabling to be determined the amount of preservative to be forced into the timber.

The relief valve having been set for to the fact that the air pressure within the cells of all a predetermined pressure, the preservative is forced into the cylinder containing the compressed air until the cylinder is filled with the preservative, the compressed air other than that filling the cells of the timber gradually finding its escapethrough the relief valve as its place is taken by the preservative forccdinto the cylinder, which continues until the cylinder is finally filled with the preservative. The'relief valve is then closcd, ar;d anadditional quantity of the preservative forccdfint the cylinder, and as this additional supply of prosi rvative must be taken care of, it penetrates the wood driving ahead of'it the compressed air in the cells further into the pores of the wood, as the pressure of (hradditional supply of preservative is in excess of the compressed air in the wood cells. The desired quan- Lily of ,bresorvativo having been driven into the pores of the 'vood,-which quantity is asccrtainablo and detcrmined by the capacity of the supply tauk, the forcing puinp is stopped in its work, and by another pump the preservative fluid in the cylinder is withdrawn. This leaves the cylinder f roe of the preserving fluid and relieved of air pressure. The prcsrval ivc having been withdrawn and the cylinder closed, air is again forced 'into'th'o cylinder-under a pressure of 50 to 100 pounds,

This pressure drives or scatters the'prosure of the fluid and not,ejecting the fluid out of the Ins-y very inore or less depending on the oonditidns to ,7 to 40 pounds, more or less, only he' maintained for with compresetluir; nextthe cylinder is filled with colle orefirst filled with com .essed air so as to exclude enter the pores of the wood of greater porosity any an iidditionsl quantity oi the preservative is added stud forced into the timber until systematic measurements pounds, or thereahout; or when a large quantity f distributes it through the cell] of the entire charge of I wood, throughout the penetrable port of the timber. This completes the process, and leaves the wood in. condition to be withdrawn and replaced by another charge.

From the foregoing it will he observed that the wood or prevent the preservative penetrating the pores or cells of the wood, thus enabling-the cells 0i all the. wood constituting the charge, and whieh'meyibe of varying degrees of porosity, to be equally brought under the influence of the compressed air so that when the preserving fluid is supplied to the (ylinder it will. not

more than it will enter the pores of the wood of greater density; that aiter'all the wood has been brought to practically the same condition of resistance to absorp tion of the fluid, the fluid is admitted to, the cylinder to fill the some, proportionately displacing the'conipressed sir whit-h finds its escape through the relief valve, the compressed air in the wood cells continuing to resist the absorption of the preservative; that an additional supply of the preservative is then weedto the cylinder, the pressure under which the same is placed (arising thefluid now to penetrate the wood cells and to drive ahead of it the air which is in the eells, the eompressetl air in ihe'rells yielding under this preseells; that the surplus fluid is then withd'nwn from the cylinder, and air pressure then applied to drive the fluid which is in the wood cells further into the penetreble portions of the wood. This insures an equahle transfusion of the preservmive throughout the pores of all the timber under treatment, Besides obtaining o uniform distribution throughtiut'euch cubic foot of the wood under treatment, it brings the quantity of pre 'servutive to penetrate the pores of the wood absolutely under the control. ofthe operator, so that more'or less of the preservative may be made to penetrate the pores of the wood as may be desired ln carrying out this'proress the degrees oipressure met at the'time. Ordinarily an air pressure of 30 apormiimstely a period of ten minutes, to till the cells thwpreservetive against the pressure mentioned; then show the desired quantity of preservative hits poliohated the pores of the wood, which may from ten -totwenty minutespmoreor lee 'w'henusing s :llflzlll quantity of the preservative and a. pressure of 50 preservative is used this period in" treatment may rovers period of twoor thr't-e hours, and under a p:-

' etanding oithe prd'cess, although as previously steted- I the pressures and the period of treatment will very' ae semisosure advancedto ul'uui 125 poundejthe preservative isthon withdrawn how the cylinder, and air pressure ranging from 80 to 100 pounds applied and maintained for say 35 minutes, more or less, or until the air gage stands 'lit the highest pressure, thus demonstratihg 1 that such pressure is uniform throughout the timber and that the air with the preservative has penetratedthe depthsof the timber. l The ioregoing is mifilcient for an iu itelligent under? 75..

cordingto conditions, but in all cases the essentiails hereinoeiore set forth should be observed. 1 This method enables a small quon'tity oi preeervin'g fluid to be equally distributed throughout all portions of a charge ofwood to be treated notwithstsnding terial differences in the natural porosity or ahsorbiitg,

powers of the different pieces oi wood. constituting the,"

,cha'rge under treatment, The result is economyh -the amount of fluid necessary, the avoidance ofi-o've'n saturation or charging of thewood with the fluid, a. more; uniform end'more thorough distribution of the fluid, and a better preservation of the wood. I

Having described. my invention and set forth merits, what I claimisz- Y p 1. in the process of nreservlng'wood, the steps conslsting in subjecting wood in a closed vessel to air pressure to charge the cells of the wood with compressed air sufllcient to prevent absorption of u preserving tluldfnnd. their Intro- '85 during u preserving fluid into the vessel. While relieving the air pressure in tho-vessel proportionately to the volume oi preserving fluid admitted, without permitting a refineas described. g 1 2. in the process of preserving wood. the stepsconslst ing in subjecting the wood in a closed vessel 'to ulrpressure ro rlmrge the cells of the wmtliwlth compressed airsufli;

cient to prevent absorption of ti'preserving fluid, that Ills, truduclng a preserving fluid, into the vessel to'replace slls placed ulr frozn the vessel while maintaining said'air pm sure in the rolls of the woodnnd then injecting additloliailli fluid into the vessel to Borerthe fluid into the bells or" wood. substantially as described v u :l, The process-o.,preservingwood. C'onslstlngin subjbcflug the wood to a elosei} vessel to or pressure tneharge the cells of the wood with air sufiit-ient to prevenuabsorp .tlon ot'n prewrrisu fluid illt'fl' introducing apreseryihg fluid into-tire vessel in t-ont'nct' with the wood while nialnraining said air pressure in the cells of the wood. then raising the'iarHsure-of the onvelopingfluld byudding addi-Z, iionzll mild to force the timid into up cells oi the wood tin-n witlnlraw the fluid from tluyvessol. and then upplying air m1 's nre to distrihuiu the tin-id in theflvrood' scrihed.

.lu res-flown whorl-oi l utlix mysignature-in preee'noe of two witnesses. Q

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